Langmuir. 2018 Mar 27;34(12):3654-3660. doi: 10.1021/acs.langmuir.7b04212. Epub 2018 Mar 15.
We reported an example of metal-organic framework (MOF)-based porous liquid by dispersing ZIF-8 ({Zn(mim)}, mim = 2-methylimidazole) nanocrystallites in ionic liquid (IL) of [Bpy][NTf] ( N-butyl pyridinium bis(trifluoromethyl sulfonyl)imide). Two essential challenges, stable colloid formation and porosity retention, have been overcome to prepare MOF-based porous liquid. Preventing ZIF-8 nanocrystals from aggregation before dispersing is vital to form a stable ZIF-8 colloid in IL via enhancing the interaction between ZIF-8 and IL. The resultant ZIF-8-[Bpy][NTf] colloid is able to be stable over months without precipitating. [Bpy][NTf] with larger ion sizes cannot occupy pores in ZIF-8, leaving the ZIF-8 cage empty for enabling access by guest molecules. The porosity of this porous liquid system was verified by positron (e) annihilation lifetime spectroscopy and I adsorption in ZIF-8 in the colloid. MOF-based porous liquids could provide a new material platform for liquid-bed-based gas separations.
我们报道了一种基于金属有机骨架（MOF）的多孔液体，它是通过将 ZIF-8（{Zn（mim）}，mim=2-甲基咪唑）纳米晶分散在离子液体[Bpy][NTf]（N-丁基吡啶双（三氟甲烷磺酰）亚胺）中制备的。为了制备基于 MOF 的多孔液体，克服了两个关键挑战，即稳定胶体的形成和保持孔隙率。在分散之前防止 ZIF-8 纳米晶体聚集对于通过增强 ZIF-8 和 IL 之间的相互作用，在 IL 中形成稳定的 ZIF-8 胶体至关重要。所得的 ZIF-8-[Bpy][NTf]胶体能够在几个月内稳定而不沉淀。离子尺寸较大的[Bpy][NTf]不能占据 ZIF-8 中的孔，使 ZIF-8 笼为空，以便客体分子进入。通过正电子（e）湮没寿命光谱和胶体中 ZIF-8 中的 I 吸附验证了该多孔液体体系的孔隙率。基于 MOF 的多孔液体可为基于液床的气体分离提供新的材料平台。
